Watch-mainspring



No. 753,584. PATENTED MAR. l, 1904.

E. P. o. KLEIN. l WATCH MAINSPRING.

APPLICATION IILED JAN. 29, 1903.

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Patented March 1, 1904.

PATENT GEEICE.

ERNEST F. O. KLEIN, OF BUFFALO, NEV YORK.

WATCH-MAINSPRING.

SPECIFICATION forming part of Letters Patent No. 753,584, dated March 1,1904.

Application iled January 29, 1903. Serial No. 140,995. (No model.)

To @ZZ ull/wm t may concer-7e:

Be it known that I, ERNEsT F. O. KLEIN, a citizen' of the United States,residing at Buffalo, in the county of Erie and State of New York, haveinvented certain new and useful Improvements in VVatch-Mainsprings, ofwhich the following is a specification.

My invention relates to mainsprings for watches, and more particularlyto the manner ofv connection thereof to the spring-barrel; and it hasfor its object the production of a simple, reliable, and flexibleconnection between the spring and its containing-barrel which willadjust itself to any angle to con- .form to the line of draft which isconstantly changing, due to the gradual unwinding ofY the spring and tothe winding up of the same, to provide an inexpensive spring which canbe quickly and conveniently attached and detached and which is providedwith a projection or barb with which a iiexible retaining piece is heldin engagement at all times irrespective of the angle of the line ofdraft thereon or the tension of the spring, to permit the outer end ofthe spring to move toward and from the confining wall of the barrel andwhen unwound to cause the outer convolution of the spring to conform tothe confining-wall, and also to prevent twisting of the outerconvolution at all times and under all conditions to which the spring issubjected.

To these ends the invention consists of the new and novel constructionof the spring and of the new and novel arrangement and combination ofparts, as will be hereinafter described, and particularly pointed out inthe subjoined claim.

In the drawings, Figure lis a sectional plan of a spring-barrel havingmy improved mainspring held therein, said spring being wound up. Fig. 2is a similar view showing the mainspring partially unwound. Fig. 3 is anenlarged sectional view of a portion of the spring and barrel. Fig. 4 isa similar view showing the connection to the barrel in a modified form.Fig. 5 is a perspective view of the outer end of the spring, showing theouter face thereof. Fig. 6 is a similar view of the outer end of thespring, showing the inner face thereof. 5o

Referring to the drawings` in detail, like numerals of reference referto like parts in the several figures.

The reference-numeral l designates the spring-barrel, which is geared toand designed to actuate the various parts of the watch-movement, as iscommon. A winding-arbor 2 passes through the spring-barrel and has theinner end of the mainspring 3 attached thereto. The said spring isprovided near its outer end with an undercut projection or barb 4, whichis formed by cutting transversely through the spring, as at 5, andbulging the same outwardly on that side of the incision nearest the end,thus forming an abutment 6, which is preferably filed to form anundercut face. If desired, the incision 5 may be made slanting, in whichcase the projection or barb would be undercut without the necessity offiling the same. By arching the abutment a strong and rigid constructionis obtained which cannot be distorted or effected in its efiiciency whenthe spring is twisted slightly and the line of draft is changedaccordingly.

A fieXible retaining-piece 7 abuts with one end against a pin or stud 8,projecting from the inner face of the wall of the barrel, and with itsother end Vagainst the undercut free edge of the projection or barb 4.This arrangement permits the said retaining-piece to move toward andfrom the circumferential wall of the barrel to adjust itself to thecondition of the spring. That end of the retaining-piece bearing againstthe stud 8 serves as a fulcrum to permit the same to oscillate, whilethe tension of the spring holds the ends of the same firmly against thestud 8 and the projection or barb 4.

By preference the ends of the retainingpiece are beveled, as at 9, tosecurely engage the stud 8 and the projection or barb 4 and to allowsufficient play to permit the same to oscillate and adjust` itself tothe various conditions of the spring.

In the modification shown in Fig. 4 the pin or stud 8 is dispensed withand the barrel end of the retaining-piece abuts against the enddefining-Wall l() of a segmental groove l1, formed in the inner face ofthe barrel and adapted to receive the entire retaining-piece when thespring is unwound.

IOO

By arranging the projection near the outer end of the spring instead ofat the outer end, as has heretofore been the practice, there isabsolutely no possibility of the spring breaking when Wound up. Thisapplies particularly to iine springs such as are used on small ladiesWatches, and it also prevents buckling or twisting of the spring, as theline of strain will always conform itself t0 the curvature of the springirrespective of what its condition may be.

Having thus described my invention, what I claim is- The combinationWith the spring-barrel, or' a mainspring held therein and having anundercut projection stamped therefrom near its ERNEST F. O. KLEIN.

Witnesses:

BERT MASON, EMIL NEUHART.

